Document FR2872491 discloses an example of such a closure cap in which the cover is connected in the conventional manner to the base by means of a film hinge or a bridge of material, so as to be pivotable between a closed position where said cover covers the upper surface of the base provided with a product dispensing orifice, and an open position where it is at a distance from the base and leaves the product dispensing orifice unobstructed.
In that document, when the cover is in the closed position relative to the base, the product dispensing orifice is sealed shut by a hollow pin projecting from the inner surface of the cover, designed to be positioned facing the upper surface of the base and entering into said orifice. In this position, the product contained in the container is brought into contact with the hollow pin and fills its inside space. When the cover is pivoted relative to the base to its open position, the inner face of the cover is visible and reveals the sealing pin filled with product, which gives the user a negative impression of the cap, especially in terms of cleanliness.
Furthermore, when the cover is in the open position, the upper surface of the base forms a product distribution surface to be touched by a user, for example with a finger, to obtain product leaving the container. Because of this, product residue can accumulate on the upper surface of the base, particularly after several uses of a container fitted with such a closure cap. When the cover is returned to the closed position relative to the base, this residue can adhere to and contaminate the inner surface of the cover, which is visible to the user when the cover is in the open position, contributing to a negative impression concerning cap cleanliness.
Lastly, in the cap according to document FR2872491, the existing sealing forces between the hollow pin and the product dispensing orifice resist the forces necessary to open and close the cover. When the user wishes to move the cover from its closed position to its open position, imparting a pivoting movement of the cover relative to the base, she has to overcome the frictional forces existing between the walls of the hollow pin and the dispensing orifice in order to withdraw said pin from said orifice and freely continue the opening movement of the cap. Similarly, when the cover is returned to its closed position, the user rotates the cover freely relative to the base, and as the hollow pin enters the dispensing orifice the user must overcome said frictional forces in order to close the cap.
This results in an impression of jerky or uneven opening and closing movements which are displeasing to the user, with a risk of spattering the product remaining on the upper face of the base and/or on the inside of the cover during these jerky movements.
This is why the sealing forces required for dependable closure of the dispensing orifice in such a design interfere with the usability and/or comfort of opening and closing the cap.
In addition, the dimensions of the hollow pin and dispensing orifice must be adapted so that the force necessary to open/close the cap is small enough to allow easy cap manipulations while being sufficiently high to reduce the risk of accidentally opening the cap, and so that the sealing force is high enough to prevent the product from escaping through the dispensing orifice when the cover is in the closed position. Thus, in the case of a pin and an orifice with complementary circular cross-sections, the diameter of said pin and said orifice must exceed a minimum value, for example on the order of 4 mm. The flow through an orifice having such a minimum diameter can give the impression of an imprecise or coarse distribution of product through the orifice.